1. Field of the Invention
The field of the invention relates, in general, to mounting, assembling, connecting, cooling, and/or sealing of individual energy storage cells in a multiple energy storage cell pack, and, in particular, to mounting, assembling, connecting, cooling, and/or sealing of individual capacitors in an ultracapacitor energy storage cell pack.
2. Related Art
An ultracapacitor energy storage cell pack includes multiple interconnected cells of individual capacitors that store an electrical charge. For vehicle applications, the ultracapacitor packaging has to provide protection against vibration, shock, temperature, and corrosive effects of water, dust, and debris in the mobile vehicle environment. The capacitors must be held in place, need to be cooled, and need environmental protection for their terminals and the copper interconnects between the capacitors.
During charging and discharging operation of the capacitors, parasitic effects cause the cell temperature to increase. Cooling is required to minimize increased temperature operation that would degrade the energy storage and useful life of the capacitor. Each capacitor includes an exterior capacitor casing and a pair of terminals. Prior mounting arrangements for ultracapacitors have held the capacitors by the exterior casing, obstructing an important part of the capacitors for efficient cooling.
In addition to the cooling problems with prior ultracapacitors, in prior ultracapacitors, capacitors have also been connected by attaching copper wire to the terminal lugs, and the terminals and interconnections have been protected by placing a seal cover on each individual capacitor. Prior ultracapacitors have also required that the monitoring and control circuits have a separate circuit board and package with a separate wiring harness connected to each of the individual capacitor terminals. Because of the complexity of these prior ultracapacitors, they require numerous components, more assembly steps, protection of the terminal and inter connections is more difficult, and a shock and vibration support structure is still required.
An aspect of the invention involves a system and method to mechanically secure, electrically connect, environmentally seal, and assemble an ultracapacitor network pack of individual capacitors. A circuit board rigidly locates the capacitors in the pack and electrically connects the capacitors into energy storage and control circuits. Copper interconnections under the circuit board are the power conductors that connect the individual capacitors. An insulated solid flat bottom plate and a cutout lattice plate with cutout holes at the other end of the cells provides a second point of location and support while allowing cooling air to circulate around a middle space. The circuit board and two foam sheet layers seal around the copper interconnections and a top rim of the capacitors. A flat transparent plastic cover is secured and sealed over the top of the circuit board to provide for visual observation of LED indicators and voltage-current displays. The whole package is bolted together and becomes a rugged power module suitable for mobile vehicular applications. The inventors of the present invention recognized that because tests show no significant temperature difference between the capacitor terminals and the capacitor case, the terminals can be sealed against the environment while allowing the capacitor to be cooled by an air stream around the surface area of the case.
Another aspect of the invention involves a method of assembling an ultracapacitor energy storage cell pack. Individual capacitors are supplied as a can with two threaded lug terminals that protrude through an insulated cover. The ultra capacitor pack assembly process starts by placing the capacitor cans onto the bottom plate through the cutout holes in the lattice plate. Next, to seal and insulate around the can tops, a sheet of foam insulator with cutouts for the capacitor terminals is laid on top of the capacitors. The copper interconnections are then placed over the capacitor terminals followed by another sheet of foam insulator with cutouts for the copper interconnections. The circuit board is added to the stack and bolted to the capacitor terminals. A top transparent cover and frame complete the assembly. The method of mounting the capacitors was developed to simplify the assembly process, keep the case open to cooling airflow, insulate the terminals, and reduce the number of parts by having the circuit board perform multiple mechanical and electrical functions. The invention is easily adaptable to large numbers of cells in various geometric configurations.
An additional aspect of the invention involves an ultracapacitor energy storage cell pack. The pack includes an ultracapacitor mounting assembly having a circuit board, a cooling assembly connected to the ultracapacitor mounting assembly and adapted to supply a cooling air stream therein, and a plurality of capacitors including a pair of terminals and an exterior casing, the plurality of capacitors mounted to at least the circuit board of the ultracapacitor mounting assembly with the pair of terminals, allowing the exterior casing to be in the path of the cooling air stream.
Another aspect of the invention involves an ultracapacitor energy storage cell pack. The pack includes an ultracapacitor mounting assembly having a circuit board, a plurality of capacitors including a pair of terminals, the plurality of capacitors mounted to at least the circuit board of the ultracapacitor mounting assembly with the pair of terminals, and a sealing material to seal the pair of terminals of the capacitors against collection of water, dust, and debris that may tend to contaminate and corrode the terminals and otherwise degrade the performance of the capacitors.
A further aspect of the invention involves an ultracapacitor energy storage cell pack. The pack includes a plurality of capacitors having a pair of terminals, a plurality of electrically conductive interconnects to connect the capacitors via the terminals, and an ultracapacitor mounting assembly to which the plurality of capacitors are mounted, the ultracapacitor mounting assembly includes means for mounting, carrying and sealing the electrically conductive interconnects, means for maintaining the position and spacing of the capacitors in an X and Y direction, means for holding down the capacitors in a Z direction, means for preventing the capacitors from rotating, and means for mounting the capacitors to the ultracapacitor mounting assembly via the pair of terminals.
A still further aspect of the invention involves an ultracapacitor energy storage cell pack. The pack includes a plurality of capacitors including a pair of terminals and a cover; a plurality of electrically conductive interconnects including holes through which the terminals may pass, the electrically conductive interconnects connecting the capacitors via the terminals; and an ultracapacitor mounting assembly to which the plurality of capacitors are mounted, the ultracapacitor mounting assembly including a bottom base plate on which the capacitors are located and a crate plate with a plurality of holes through which the capacitors are received, a box frame including large lower and upper openings through which the capacitors extend, a first insulating and sealing sheet located on the cover of the capacitors and including a plurality of holes through which the terminals protrude, a second insulating and sealing sheet located on top of the first sheet and including a plurality of holes that receive the plurality of electrically conductive interconnections, the holes of the electrically conductive interconnections receiving the terminals of the capacitors, one or more circuit boards located on top of the second insulating and sealing sheet and including holes through which the terminals protrude, and fasteners to attach the terminals to the one or more circuit boards to compress the first and second insulating and sealing sheets in between the cover of the capacitors and the one or more circuit boards, and secure the capacitors and electrically conductive interconnections in position.
An additional aspect of the invention involves a method of assembling an ultracapacitor energy storage cell pack having a plurality of capacitors with a cover, a pair of terminals protruding from the cover, an exterior casing. The method includes inserting a plurality of capacitors through holes in a crate plate, on top of a bottom base plate; disposing a box frame over the capacitors so that the capacitors extend through large lower and upper openings of the box frame; placing a first insulating and sealing sheet on top of the capacitors so that the terminals protrude through holes in the sheet; placing a second insulating and sealing sheet on top of the first sheet, the second insulating and sealing sheet including a plurality of holes to receive a plurality of electrically conductive interconnections; locating a plurality of electrically conductive interconnections in the plurality of holes of the second insulating and sealing sheet so that the terminals of the capacitors extend through holes in the electrically conductive interconnections; placing one or more circuit boards on top of the second insulating and sealing sheet so that the terminals protrude through the one or more circuit boards; and attaching the terminals to the one or more circuit boards using fasteners, compressing the first and second insulating and sealing sheets in between the cover of the capacitors and the one or more circuit boards, and securing the capacitors and electrically conductive interconnections in position.
Another aspect of the invention involves a method of cooling capacitors of an ultracapacitor energy storage cell pack. The method includes providing an ultracapacitor energy storage cell pack having an ultracapacitor mounting assembly including a circuit board, and a plurality of capacitors including a pair of terminals and an exterior casing, the plurality of capacitors mounted to at least the circuit board of the ultracapacitor mounting assembly with the pair of terminals; and supplying a cooling air stream over the exterior casing of the capacitors to cool the capacitors of the ultracapacitor energy storage cell pack.
A further aspect of the invention involves an ultracapacitor energy storage cell pack. The pack includes an ultracapacitor mounting assembly including a circuit board with a plurality of holes, and a plurality of capacitors including terminals, the terminals received by the holes of the circuit board to mount the plurality of capacitors to the circuit board of the ultracapacitor mounting assembly.